Here's the only photo I could find of her in McQ, with a review that I pretty much completely agree with.

http://markvoger.com/2015/07/mcq-1974/

I find it on a par with the Dirty Harry movies, with some cheap lines here and there, but overall very enjoyable, about a cop who operates with his own code a little bit outside the law. And like the Dirty Harry movies, very evocative of the mid 1970's. Even as the Dirty Harry sequels extended into the early/mid 1980's, they still remained evocative of the 1970's, with a few 80's elements tacked on, but grumpily clinging to an earlier era.

Julia Adams plays his ex-wife, and you can read unspoken feeling as his ex-wife, her new husband, and his daughter, as he walks away to his car and then drives off, where he's clearly going on an unspoken (and dangerous) personal mission.